Universe Guide

AI Cephei

AI Cephei Facts

  • AI Cephei is a eclipsing main sequence star that can be located in the constellation of Cepheus. The description is based on the spectral class.
  • AI Cephei is not part of the constellation outline but is within the borders of the constellation.
  • Based on the spectral type (B0.5V:pvar) of the star, the star's colour is blue .
  • The star can not be seen by the naked eye, you need a telescope to see it.
  • The star is calculated at being about -3624.04 light years away from us. Distance

AI Cephei's Alternative Names

HIP107500 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD239767.

AI Cephei has alternative name(s) :- AI Cep, AI Cep.

BD number is the number that the star was filed under in the Durchmusterung or Bonner Durchmusterung, a star catalogue that was put together by the Bonn Observatory between 1859 to 1903. The star's BD Number is BD+56 2640.

More details on objects' alternative names can be found at Star Names .

Location of AI Cephei

The location of the main sequence star in the night sky is determined by the Right Ascension (R.A.) and Declination (Dec.), these are equivalent to the Longitude and Latitude on the Earth. The Right Ascension is how far expressed in time (hh:mm:ss) the star is along the celestial equator. If the R.A. is positive then its eastwards. The Declination is how far north or south the object is compared to the celestial equator and is expressed in degrees. For AI Cephei, the location is 21h 46m 22.60 and +56° 55` 01.8 .

Physical Properties of AI Cephei

AI Cephei Colour and Temperature

Based on the star's spectral type of B0.5V:pvar , AI Cephei's colour and type is blue main sequence star. The star has a B-V Colour Index of 0.57 which means the star's temperature is about 6,006 Kelvin. The temperature was calculated using information from Morgans @ Uni.edu.

AI Cephei Apparent and Absolute Magnitudes

AI Cephei has an apparent magnitude of 9.24 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. Using the supplied Parallax value, you would get an absolute magnitude of Magnitude, whether it be apparent/visual or absolute magnitude is measured by a number, the smaller the number, the brighter the Star is. Our own Sun is the brightest star and therefore has the lowest of all magnitudes, -26.74. A faint star will have a high number.

Distance to AI Cephei

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as -0.90000 which gave the calculated distance to AI Cephei as -3624.04 light years away from Earth or -1111.11 parsecs. If you want that in miles, it is about -21,304,373,497,432,329.98, based on 1 Ly = 5,878,625,373,183.61 miles.

Variable Type of AI Cephei

The star is a eclipsing Beta Lyrae (Sheliak) variable type which means that its size changes over time. The Variable Type is usually named after the first star of that type to be spotted. AI Cephei brightness ranges from a magnitude of 10.001 to a magnitude of 9.300 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 4.2 days (variability).

Source of Information

The source of the information if it has a Hip I.D. is from Simbad, the Hipparcos data library based at the University at Strasbourg, France. Hipparcos was a E.S.A. satellite operation launched in 1989 for four years. The items in red are values that I've calculated so they could well be wrong. Information regarding Metallicity and/or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

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Additional AI Cephei Facts and Figures

Visual Facts

Primary / Proper / Traditional NameAI Cephei
Alternative NamesAI Cep, HD 239767, HIP 107500, BD+56 2640, AI Cep
Spectral TypeB0.5V:pvar
Constellation's Main StarNo
Multiple Star SystemNo / Unknown
Star Type Main Sequence Dwarf Star
GalaxyMilky Way
Visual / Apparent Magnitude9.24
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)21h 46m 22.60
Declination (Dec.)+56° 55` 01.8
Galactic Latitude2.64899355 degrees
Galactic Longitude99.67681092 degrees
Distance from Earth-0.90000 Parallax (milliarcseconds)
 -3624.04 Light Years
 -1111.11 Parsecs
 -229,181,291.91 Astronomical Units
B-V Index0.57

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Variable Star Details

Variable Star ClassEclipsing
Variable Star TypeBeta Lyrae (Sheliak)
Mean Variability Period in Days4.225
Variable Magnitude Range (Brighter - Dimmer)9.300 - 10.001

Estimated Calculated Facts

Effective Temperature6,006 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

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